Propeller.



G. GAYS.

FROPBLLER.

APPLIUATION FILED JUNE 16, 190e.

Eatented May 17, ww.

ANDRZW E. unAHAM GIUSEPPE GAYS, OF LOS ANGELES, CALIFORNIA.

PROPELLER.

naartoe.

Specification of Letters Patent.

Patented May 1'?, limiti.,

Application led Tune 16, 1908. Serial No. 438,818.

To all whom fit may concern:

Be it known that I, GIUSEPPE Gars, a subject of the King of Italy, who have declared my intentions of becoming a citizen of the United States residing at Los Angeles, in the county o Los Angeles and State of California, have invented new and useful Improvements in Propellers, of which the following is a specification.

This invention relates to propellers; and it has for its object to provide an improved device of this character, particularly adapted for aquatic use, which will be relatively simple and inexpensive in construction, positive in operation, and generally superior in point of efficiency and serviceability.

A particular object of the invention is the provision of a propeller for vessel-propulsion, which shall `possess a relatively increased degree of operative thrust upon thev resisting water, to the end that the water set in motion by the revolution of the propeller shall be utilized as a bearing agency for the propeller through an increased range of propulsive activity, from the point at which the forward portion of the propeller first cuts or engages with a given mass of water to the point at which such mass of water is iinally thrown or discharged from the propeller. To this end, I provide propeller members or blades having varied thrust area or operative superlicial dimensions; the relative arrangement of said members or blades being such that the member having the least or smallest thrust area is rst engaged with a given mass of water, and the member having the most or greatest thrust area is last engaged with said mass of water; one or more members being provided intermediate of those recited with respect to operative position and application to the water and with respect to thrust area. In the employment of a propeller constructed in accordance with the general arrangement, conformation and provision of parts last recited, the water is picked up dead by the foremost propeller member and is gradually put in motion as it acts as a bearing in resistance, to the screw action of the propeller, finally leaving the rearmost propeller member at such accelerated speed that its further utilization as a resistance or thrust resistance is substantially null.

In the emplo ment of a propeller of the character described, smoothness of operation and lack of vibration accompany the actuation of the propeller, together with a saving pf 1pressure medium and consequently of The propeller may be fitted to vessels of standard construction, to which such minor alterations for its reception may be made, as in any particular instance are found necessary.

The invention consists in a novel provision, construct-ion, combination, association and relative arrangement of parts, members and features, all as hereinafter shown and described and l'inally pointed out in claim.

In the drawing z-lt`igure l is a side view of a propeller constructed according to the invention, a portion of a vessel being shown in dotted lines as tted with said propeller; and Fig. 2 is an end view of the same, looking in the direction of the arrow, Fig. l.

Corresponding parts in both the figures are denoted by the same reference character.

Referring with particularity to the drawing, A, B and C designate respectively, the members of a propeller embodying the invention, in the present instance three of such members or blades being employed. tach of said members or blades represents a portion of the thread of a screw, all of such represented threads having the same pitch; and the stem of said represented screw coincides with the tail shaft D with which the propeller members A, B and C are combined and associated. The thrustareas or operatively superficial dimensions of the members or blades A, B and C vary from and including' the member A to and including the member C; so that the member A has the least or smallest thrust area and the member or blade C has the most or greatest thrust area; the said variations in the thrust areas or operatively supercial dimensions corresponding to variations in the depth of cuts of the threads of screws. The member of blade A is located nearest adjacent to the forward or inner end portion ci of the tail shaft D; the member C is located nearest adjacent to the outer or rearward or outer end portion Z; of the tail shaft; and the member or blade 'B is arranged intermediate of the members A and C. Each of the spiral members or blades extends approximately through 18()o of a circle, being fixed at its inner portion to the tail shaft D; and the outer edge portions, c, Z and c, respectively, of the propeller member or blades project radially and 0bliquely from the tail shaft D; the edge portion c, overlapping the thrust area of the member or blade B; and the edge portion Z overlapping the thrust area of the member or blade C; to the end that the water passing from the member A is imposed upon the member B and is thence passed to the member C and finally discharged therefrom. The inner portions of the members or blades A, B and C, which connect with the tail shaft D, successively overlap.

The operation, method of use and advantages of the improved propeller constituting the invention will be readily understood from the foregoing description taken in connection with the accompanying drawing and the following statement The member or blade A, leading the other blades, and being first to cut the water, having the smallest or least thrust area, and the thrust areas of the other members or blades being` relatively greater, that of the member or blade C being the greatest, and all of said blades having the same pitch; which results that the dead water encountered bythe blade A will thereby be set in motion, so that when discharged from the blade A to the blade B itwill offer less thrust bearing or resistance at any one point of the blade B. But the blade B having more or greater thrust area than the member A it will act upon a greater volume of water than that coming directly into contact with the blade A and thus obtain relatively as much purchase or thrust, .in total, as the blade A obtains. The saine statementhol-ds substantially true in comparison of the action of the blade C relative to the action 'of p the blade B. `When the moving water is linally discharged from the member C it will have become set in motion, by the three propeller blades, to an extent rendering i-ts further utilization as thrust resistance substantially null. It is manifest, therefore, that by the use of the propeller organized as shown and described, substantially all of the inertia of the water engaged by the propeller is utilized as a purchase for the propeller in its screw action. The overlapping arrangement of the propeller member or blades tends to impart a smooth even motion in the action of the propeller, lessening the jar and vibration usually attended upon propeller action; and the entire operation of the propeller, combining high efliciency and smoothness tends to serve the actuating pressure medium, such as steam, and work a saving of fuel.

l do not desire to be understood as limiting myself to the specific construction, provision, combination, association, and relative ar angement of parts, members and features shown and described; but reserve fthe right to vary the same, and adapting the improvements to varying conditions of use, without departing from the spirit of the invention or the terms of the following claim.

Having thus described my invention, l claim and desire to secure by Letters Patent:-

An improved propeller having a plurality of spiral members or blades, the inner portion of each of which overlaps the inner portion of each of the others; said spiral members or blades having varying thrust areas or operative superficial dimensions and being of the same pitch, each of said members extending approximately through 180 degrees of a circle; the outer edge portions of said spiral members or blades projecting radially and obliquely from the axis of the propeller; and said outer edge portions overlapping respectively the thrust areas of the adjacent members or blades.

ln testimony whereof, l have signed my name to this specification in the presence of two subscribing witnesses.

GIUSEPPE GAYS.

lVitnesses CAL F. HUNTER, RAYMOND l. BLAKESLEE. 

